In recent years there has occurred a vast increase in the amount and complexity of biomedical testing. To perform each test manually may be time consuming and expensive. Consequently, many physicians send body fluid samples, such as blood samples, to central laboratories for testing. However, the transportation of the samples to the central laboratory may not be convenient and the testing by the central laboratory may involve unnecessary expense.
The testing apparatus designed for central testing laboratories is generally complex and expensive, costing many thousands of dollars. Such machines are not suitable for use in physicians' offices, where the tests may be performed by relatively untrained personnel.
There is an increased need for a semi-automated system to analyze blood and other biological fluids. The requirements of such a system are that (a) it must be as automatic as possible, with as few as possible manual operations to be carried out by the technician; (b) it must be self-contained, both to increase sample sterility and to eliminate possible sample confusion; and (c) it must be sufficiently compact and inexpensive to be within the financial range of the small medical practitioner, and suited for his uses.